hanky-panky

noun

Anything dishonest, deceptive, or unethical; esp, in recent use, sexual infidelity; monkey business: She seems just to be along for some hanky-panky with her pal, General Von Griem/ can be an assurance against clandestine wrongdoing and political hanky-panky(1841+)

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.Copyright (C) 2007 by HarperCollins Publishers.Cite This Source